1. Field of the Description
The present description relates, in general, to creating realistic skin or skin systems fix robots or for use with robotics or other applications in which skin or similar coverings are applied (e.g., robotics used to simulate movement of a human's or a character's face, hands, or the like). More particularly, the description is directed to methods of fabricating skin systems (and skins formed using such methods) for applying over robotics that better facilitate connection to robotic actuators or drivers so as to enhance durability of the skin while also providing more realistic skin movements such as facial expressions or movement while the character is “speaking” (e.g., providing natural lip, mouth, and surrounding facial feature movement when a robotic head is operated to simulate speaking).
2. Relevant Background
Durable materials that are often also flexible and elastic such as plastics and rubbers are used in many applications to create coverings or skins that are applied over an internal physical support structure or skeleton. For example, skins or skin systems are used to create realistic models of humans, animals, and characters, and when combined with robotics, such models may accurately simulate live beings.
Robotics involves the design and use of robots such as to provide programmable actuators or drivers to perform tasks without human intervention, and there have been significant demands for robotic devices (or robots as these terms may be used interchangeably) that simulate humans, animals, and other living beings or characters. These robotic characters are relied upon heavily in the entertainment industry such as to provide special effects for movies and television and to provide robots for use in shows and displays in amusement or theme parks. For example, robotics may be used to provide a character in a theme park ride or show that repeats a particular set of movements or actions (e.g., programmed tasks) based on the presence of guests or a ride vehicle or another triggering event.
It is likely that the interest in robotics will continue to expand in the coming years, and a growing area of interest is how to provide robots that appear more realistic. Many robotics companies have focused on creating robots with software, processing hardware, and mechanical actuators or drivers that allow the robots to behave more like the natural creature that is being simulated. Much work has been done to create robots that can move and even, behave similar to humans such as by manipulating objects with mechanical assemblies that behave like hands configured to be human-like. Significant effort has also been directed to providing robots with realistic facial animation such as having a robot open and close its mouth to provide lip synchronization with output audio (e.g., with speech) and by providing particular facial movements including eye movement such as frowning, smiling, and the like. While many advances have been made in realistically simulating the physical movement and facial movement of a character, problems with maintaining a realistic or desired movement or facial animation still occur when the robotics (e.g., internal components of a robot including mechanical/structural portions as well as software, hardware, power systems, and the like) are covered with a skin or skin system. For example, a robot used to simulate a particular creature would be covered with skin or a covering assembly to imitate the natural or desired covering for the creature such as skin and fur/hair for many creatures, clothes for some creatures such as humans or characters (e.g., characters from animated films or television or puppets), or a more fanciful covering system such as a metallic suit or any other desired covering.
In simulating humans or human-like characters, the robotics are typically covered in a skin that is fabricated of flexible material to move naturally with the underlying robotics. The skin may be formed of a rubber material or a silicone that is attached or anchored to the mechanical actuators or drivers of the robotic system, and the skin is configured to have an outward appearance similar to the character or creature being simulated by the robot. For example, the facial skins can he formed so as to have an uncanny resemblance to the character (or person) they are imitating, but often this resemblance ends when the attached robotics begin animating the face. The connection or anchoring points become apparent as the skin is pulled or pushed from behind. Additionally, the movement may be undesirably localized with movement, only at the point of attachment, whereas a human face generally stretches and contracts more as a unit (or the movement is more widespread across the face), e.g., a human's skin around their nose and eyes may move when skin around the mouth moves while a typical robotic skin may only move near the connection point with the manipulating robotics.
Currently, a skin system for a robot is made using a manual process relying on skill and experience of the craftsperson creating the skin and requiring many man-hours to prototype and later fabricate based on the prototype. In the existing process, a sculpture is created, such as from clay or other moldable/shapeable materials, to represent the exterior skin shape (e.g., a person's face, a character from a movie, and so on). The sculpture is then molded, and sheet wax or a layer of clay is laid by hand into this exterior mold to define a desired thickness for the exterior skin layer. An interior core is then fabricated by hand such as by using fiberglass and resin. Fiberglass or a similar material is used to form a mold from this core, and hard shells, e.g., fiberglass shells to support the skin when the robot is later assembled, are then created from this core mold. An exterior skin can finally be formed by pouring a rubber or other flexible material into the gap between the exterior mold (with the sheet wax removed) and the core mold. After it is set, the skin is removed from the molds and placed on the supporting or hard shell(s) and attached to portions of the robotics.
As discussed above, the realism of the movement of the skin may be spoiled as the skin moves more or unrealistically at the connection point between the skin and the robotic driver or actuator. Presently, the connection points are provided after the skin is removed from the mold. Application of the connection points may involve gluing a dot or connection point component onto the inner surfaces of the skin, and then connecting the connection point component to the robotics. For example, the connection point may be configured as a socket of a rubber or soft material similar to that of the skin, and the robotic actuator may have a ball-shaped head at its end so as to provide a ball and socket-type attachment at this point of the skin when it is inserted into the connection point component. Glue may also be used to bond snaps, Velcro or similar fabric, metal/plastic plates with holes, and the like onto the inner or back surface of the skin that then mates with the robotic actuators so as to affect skin movement. Instead of using glue, some mounting techniques call for melting the hardened skin and then adding snaps or pads to the skin surfaces.
These techniques for providing connections with between the skin and robotics have not been entirely successful in meeting the needs of the robotics industry. Each of these processes is post-skin making such that the connecting components will often not effectively stand up under ongoing wear and tear of a repeated motion of the underlying or driving robotics. The non-integral components, which are often of an incompatible or non-similar material, tend to tear or work their way out of the skin or break the glue-based bonding to the skin. The use of dot or point connection points often will not provide a realistic movement of the skin as the forces applied by the robotics actuators or drivers are applied as point forces. Since the connection point components are added after the skin is removed from the core and mold, the application of the connectors often relies on the skill and experience of the artisan and is difficult to accurately position each of the connectors so as to obtain a desired and predictable connection location on the skin surface with the robotics (e,g,, two people may glue the same connection component at two slightly offset location so as to create differing skin movements with similar robotics actuation).